Pixargus GmbH Automation by Vision

Pixargus: Automatic defect density evaluation takes yield management out of the grey area

ProfilControl Surface systems inspect the surfaces of profiles made of plastics or rubber.

New surface inspection module has a handle on complex user requirements specifications

At “K 2013”, Pixargus will be presenting its new “Defect Density Management” solution for the surface inspection of profiles made of plastics or caoutchouc. With this system, it is possible to combine the evaluation of surface defect types and count over a defined length of the product. Profile manufactures will be able to fulfill even highly complex requirements specifications set up by their customers, while minimizing the out-of-spec rate.

The new Defect Density Management (DDM) module makes it a lot easier for profile manufacturers to produce exactly to customer specifications. They will from now on also ship products which in the past would have been graded as “out-of-spec” because of a subjective evaluation based on vague criteria.

The module belongs to the family of Pixargus ProfilControl Surface (PCS) systems, which inspect the surface condition of profiles in an inline procedure.

Optical inline inspection systems have reached a high standard in detecting and classifying surface defects on profiles. However, the contextual evaluation of defects, which includes logical operations between defect criteria, has so far remained in the grey area.

In numerous specifications, especially those set up by automotive producers, the “ship or block” decision depends on OR-operations. A customer may reject a profile, for example, if over a specified length of the product there is one severe defect or one medium defect plus several small defects.

Human inspectors would be unable to cope with such logical operations while doing visual inline inspections of the product. They would be able to base their decisions but on subjective impressions. The Defect Density Management solution, however, weights every single surface defect and sums up the obtained values over a certain length of the product. The inspection system sends out a signal as soon as the value exceeds a defined threshold. The signal can be used to mark out-of-spec sections of the profiles or control downstream cutting and sorting equipment. This relieves the human inspector from the monotonous task of visual checks and painstaking sorting of the profiles into good or bad.

The direct feedback of ProfilControl 6 data into the process makes it possible to correct the production process without delay, ensuring that defects do not continue along the profile.